It seems like it might be feasible for a proxy war (like the one in Syria) to escalate significantly, to the point where multiple major powers are contributing

It seems like it might be feasible for a proxy war (like the one in Syria) to escalate significantly, to the point where multiple major powers are contributing manpower and materiel directly to the front lines; In such a case, it may be possible for an extended war to take place, while still incentivizing deployment of autonomous weaponized platforms - which are already in development today [1]. [1] https://en.wikipedia.org/wiki/Lethal_autonomous_weapon https://en.wikipedia.org/wiki/Lethal_autonomous_weapon